Keeping it illegal supports a large prison-industrial complex, takes otherwise relatively benign and productive people and ruins their lives far out of proportion to the offense, and helps to continue to fund large organized crime operations, probably with ties to human trafficking and larger things than selling marijuana, and gives law enforcement further excuse to practice civil forfeiture (seizing property without due process of law) and gives them one more excuse to justify curtailing other civil liberties in pursuit of the "war on drugs."

I don't see you calling for any moral responsibility there.